Radioisotope Half-Life Calculator

What is Half-Life?

Half-life is the time required for half of a given quantity of radioactive material to decay. It is a characteristic property of each radioisotope.

Half-Life Properties

Important characteristics:

• Constant for each isotope
• Independent of initial amount
• Independent of physical conditions
• Related to decay constant: t₁/₂ = ln(2)/λ

Common Half-Lives

Examples of radioisotope half-lives:

• Carbon-14: 5,730 years
• Uranium-238: 4.47 billion years
• Iodine-131: 8.02 days
• Cobalt-60: 5.27 years

Applications

Half-life calculations are used in:

• Radiometric dating
• Nuclear medicine
• Radiation safety
• Nuclear waste management

Multiple Half-Lives

After n half-lives:

• 1 half-life: 50% remains
• 2 half-lives: 25% remains
• 3 half-lives: 12.5% remains
• 10 half-lives: ~0.1% remains